Guide to Spoofing Attacks: How to Prevent Them

Judging its light-hearted name, ‘spoofing’ may seem harmless at first glance. However, it’s one of the most serious types of cyber attacks, responsible for millions of dollars in losses each year. Since spoofing attacks can be hard to detect, they can allow attackers to hide in networks for months, giving them plenty of time to steal important data, inject systems with malware, and much more.

A serious spoofing attack can cripple any enterprise—especially small businesses who have less of a financial buffer to fall back on. As a result, it’s crucial that all organisations wise up to spoofing attacks, putting greater emphasis on understanding and preventing them.

Here’s a guide on the basics of spoofing attacks and what you can do to stop them from ruining your business.

What is a Spoofing Attack?

Before the advent of cyber attacks, the word ‘spoofing’ was used solely to describe a comedic imitation. Online spoofing attacks got their name because they also involve imitation, but there’s nothing funny about them. In fact, despite getting less press than ransomware and other types of cyberattack, they can be just as harmful—if not more so.

Simply put, spoofing is the practice of imitating a party or device in order to trick another party or device for malicious or fraudulent purposes. This definition may sound vague, but that’s because spoofing can take many forms, each with its own specifics.

Some of the most common types of spoofing attack are as follows.

Types of Spoofing Attacks

1. IP Address Spoofing Attacks

IP address spoofing is one of the most common forms of a spoofing attack.

The transmission of IP packets forms the basis of most communication between networked devices today. Alongside its body content, every IP packet contains a header which includes a source address. Typically, this source address belongs to the sender of the packet. However, during an IP spoofing attack, the attacker creates and sends IP packets with a spoofed source address.

Alongside being one of the most prevalent spoofing attacks, IP spoofing is also one of the most varied. In most cases, IP spoofing is used to launch a DDoS (direct denial of service) attack, flooding networks with traffic by disguising malicious IP packets as packets from legitimate addresses. There are two main IP spoofing methods used in these attacks:

The masked botnet method: In this method, attackers use botnet devices to infiltrate and flood servers, sending multiple packets with spoofed addresses to hide the identity of the devices. This allows attackers to execute a successful DDoS attack without being detected by the target, law enforcement, and even many DDoS-mitigation tools.

The reflected attack method: In this method, the attacker spoofs the target’s IP address and uses it to generate and send falsified packet requests to other network devices. This triggers an automatic response, sending a flood of response packets back to the target. This method is used in a variety of DDoS types, including NTP amplification, DNS amplification, and Smurf attacks.

On top of these attack methods, IP spoofing can also be used to bypass authentication on trust relationship-based networks. These networks only require an IP address to verify the identity of a device trying to access the network. Spoofing one of these IP addresses gives attackers a simple way around the network’s security measures, instantly granting them access permissions.

2. ARP Spoofing Attack

ARP spoofing is another frequently used attack which can have very serious consequences for organisations, particularly with regard to data theft.

Used in data transmission, ARP (which stands for Address Resolution Protocol) is a protocol which links IP addresses to MAC (Media Access Control) addresses. During an ARP spoofing attack, the attacker sends a spoofed ARP transmission across the network, thereby linking their MAC address with a legitimate IP address on the network. Once the attack has been successfully executed, the malicious party can receive, block, and modify data intended for the host IP’s address.

One of the most common purposes of an ARP attack is to steal sensitive information from the target. However, that’s not its only use. ARP spoofing can also be used as part of a DoS attack, resolving the target’s MAC address with multiple IP addresses to flood the target with traffic. Session hijacking (gaining access to a system by stealing its session ID) and man-in-the-middle attacks (used to intercept traffic between targets) can also be executed using ARP spoofing.

When it comes to preventing ARP spoofing attacks, it’s important to note that they can only be performed on networks that use the Address Resolution Protocol.

3. DNS Server Spoofing Attack

DNS spoofing is another way attackers exploit system vulnerabilities by falsifying network identities. To put the power of DNS spoofing into perspective, the vulnerability it exploits was also responsible for the ‘Great Firewall of China’ spreading to the US in 2010, blocking American residents from accessing popular websites like Twitter, Facebook and more.

One of the core systems of the internet, the Domain Name System (more commonly known as DNS) links domain addresses with their corresponding IP addresses, allowing devices to load internet resources efficiently. Unfortunately, like many other essential systems, it can be exploited by spoofers.

In a DNS spoofing attack, the attacker manipulates a DNS server to redirect a domain name to an IP address they control. This is used as a foundation to allow attackers to steal sensitive data, spread malware, and more. In some cases, the website on the attacker’s IP address mimics the target website exactly, making it DNS attacks very hard to spot. As with all the above types of spoofing attack, DNS spoofing can be carried out for a variety of purposes using multiple methods.

One of the most well-known forms of DNS spoofing is DNS cache poisoning. DNS servers keep up speed and efficiency with caching between other servers, but this leaves them open to attack; once attackers inject spoofed DNS entries into the server, all nodes connecting to it will use that entry until the cache expires. Worse, DNS poisoning can quickly and easily spread if other servers (such as home router servers) are pulling their information from the compromised target server. DNS spoofing can also be used as part of a man-in-the-middle attack, among others.

How to Prevent Spoofing Attacks?

Once you understand how spoofing attacks are commonly used to bring harm to organisations, you can better understand how to prevent them. One important thing to note is that in the vast majority of cases there is no way to stop a malicious party from launching a spoofing attack. As such, the best way to prevent spoofing is by adding more layers of security to your network so attacks cannot get through. Here are some of the security methods you can use.

Use Packet Filtering

One of the best all-round ways to prevent spoofing attacks is to use packet filtering. Ingress packet filtering is a firewall technique that monitors all incoming packets, catching and blocking all those that show a conflict between their source of origin and their source address. There is also a second form of filtering—egress packet filtering—which does the same for outgoing packets, preventing attackers from launching attacks from within the network. Packet filtering is most commonly used as a preventative tool against IP spoofing, but it’s also a useful tool against ARP spoofing, monitoring for conflicts between MAC and IP addresses.

Use Encrypted Protocols

Another very efficient prevention method is using secure, cryptographic network protocols such as HTTPS (HTTP secure), SSH (Secure Shell) and TLS (Transport Layer Security). These protocols encrypt outgoing data and authenticate incoming data, thereby preventing attackers from intercepting and modifying said data even if they’ve executed a spoofing attack.

Don’t Use Trust Relationships

As noted above, IP spoofing can be used to illicitly gain access to any network using trust relationships as an authentication method. This can have disastrous consequences for any organisation. Unsurprisingly, the best way to prevent this spoofing method is to avoid using trust relationships on your network. Logins are a far more secure method of verifying devices.

Use Spoofing Detection Software

Similar to how anti-virus software is one of the best ways to block malware, anti-spoofing software can be a useful tool in your arsenal against blocking spoofing attacks. Said software inspects and verifies all data transmissions, helping to catch and block any submissions it believes to be spoofed. While spoofing detection software should not be relief upon as your sole spoofing preventative, it’s a good way to bolster security.

Get a VPN

Last, but not least, a VPN is a good all-round security tool that organisations should make use of. A VPN (short for Virtual Private Network) encrypts all the traffic transmissions from a device. This ensures that even if you fall victim to a spoofing attack, the attacker won’t be able to intercept or modify any of your data. One possible cybersecurity VPN to try is NordVPN; however there are many good VPNs, you just need to choose carefully.

Ultimately, the best way to reduce your risk of falling victim to a spoofing attack is to bolster your security in as many ways as possible. All of the suggestions above will help to protect you, but no one option represents a full solution. Using all possible prevention techniques will ensure you’re protected against as many angles as possible, which is key when it comes to a type of attack with so many variations.